Phowograph-hobh



C H. LARSSON.

PHONOGRAPH HORN.

APPLICATION HLED Nov.22. I9l8.

' L323fi77, Patented Dec. 2, 1919.

fJj. .l.

INVENTOR dar/ 17. Lawson I ATTORNEY CARL HJ'ALMAR LARSSON, 0F SEATTLE,WASHINGTON.

PHONOGRAIH-HORN.

To all whom it may concern:

Be it known that I, CARL HJALMAR LABS SON, a subject of the King ofSweden, and resident of the city of Seattle, county of King, and Stateof Washington, have invented certain new and useful Improvements inPhonograph-Horns, of which the following is a specification.

My invention relates to phonographs and like machines used forreproducing sounds through the medium of a record and consists of anapparatus to be attached to the tone arm of a machine and to serve thesame purpose as the horn, namely, to amplify the sound and modify itstone.

The object of my invention is to produce a device of this sort whichwould ordinarily be installed in the cabinet or case upon which thephonograph is supported and which will improve both the volume of soundand quality 'of tone.

The features of novelty in my invention will be hereinafter describedand then particularly defined in the claim.

In the accompanying drawings I have shown the same embodied in the typeof construction which I now prefer.

lFigure 1 is a vertical section or elevation of my device.

Fig. 2 is an elevation, in partial section,

. of the same.

As I have shown the device in the drawings, it is embodied within acasing l, which casing may be constructed in any suitableor desiredmanner. This is illustrated as a plain casing. It may be given all theornasmall size at the point where it connects with the tube 2 and isexpanded therefrom set that in one direction it is in width the same asthat of the casing. This is indicated by the dotted lines in Fig. 2. Inthe other way, or as shown in cross section in Fig. 1, it expands to asize somewhat less than half the width of the casing inthis direction.

Specification of Letters Patent.

Patented cc. 2, it f Application filed November 22, 1918. Serial No.263,642.

The lower edge of this section 3 is supported at one side from a ledge40- which is carried by the lower edge of a diaphragm l, which dlaphragmis preferably made as a wide board which extends entirely across thecase or cabinet, and which is close to, but not directly in contactwith, the adjacent side of the horn 3. The intention is that the wallsof the horn shall be entirely disconnected from all parts of the casingto as full an extent as feasible.

I The lower edge of this horn section, at the opposite side, issupported from the side wall of the casing, as by means of a strip 30,which is secured to the casing and upon which the lower edge of thiswall of the horn rests. The lower edges of the horn are preferably fixedin position by gluing. A return bend extension of the horn is formed bya diaphragm 5 which extends in a curve from the strip 30, around to aconnection with the opposite wall of the case or cabinet 1. Thisdiaphragm is preferably made of thin wood veneer, which veneer ispreferably of a compound construction, that is, of a plurality of layerswhich are glued together, these layers being so disposed that the grainof adjacent layers cross.

The diaphragm 5 should be placed at such an elevation that its centralportion' does not contact with the bottom of the casing. Its side edgesextend, however, to the side walls of the casing. The intention is tomount this diaphragm in such way that its resonance and the vibrationsproduced by the sounds, will not be interfered with. This diaphragm willbe fixedly secured only at its ends, that is, to the side walls ofthecasing. Before insertion in the device it is in fiat condition and willbe sprung into place when inserted. It is, therefore, under tension.

The board 4, which forms a diaphragm extending across the casing, Iprefer to secure to the side walls by means of glue and dowel pins, as41. The purpose of this form of construction is to secure a resonantcondition in all parts of the structure and to have no nails or anythingof that nature used where it can well be avoided and thus to preventinterference with the tonal and resonant qualities of the construction.

Extending from the upper edge of the board 4 is another curved diaphragm6. This diaphragm is preferably of the comroe 'lllg employed for thediaphragm 5. I also sprung into position in a similar man-' ner. Itconnects the upper edge of the board 4 with the upper edge of an opening12 in the front side face of the casing. It thus forms a deflector forthe sound.

At its upper edge this is secured in lace by resting in a notch formedby the strip 60 and the front wall of the casing. At its lower edgeit'is inset into a notch formed at 42 in the upper edge of the board 4.It may be securely fixed therein by gluing. Thls diaphragm is thus ofsuch a construction that it is highly resonant and also has good tonalqualities.

At the front side of the casing I prefer to employ another diaphragm 8,which diaphragm extends from the upper forward edge of the curveddiaphragm 5, upwardly to a point even with the lower edge of the opening12 in the case. This diaphragm 8 p is mounted so as to be sli htlyremoved from .rectangular or quadrilateral outline.

the casing 1, so that it is free to vibrate. V

The construction above described forms what may be called a horn, whichhas two sections lying substantially parallel with each other andconnected 'by a return bend get a volume of sound which could nototherwise be obtained and also, by reason of its size and the manner ofconstructing and supporting the sidewalls of the horn, to get a softnessof tone and a qualitywhich is otherwise difiicult to obtain.

In this connection I prefer to employ,

graphic music.

for the tube 2, which connects the upper end of the horn proper with thetone arm, some vnonresonant material, as for instance, lead pipe. I havefound that the use of a tube of this character at this point cuts outmuch of the scratchy sound often found. in phono- The cabinet may beprovided'with' a recess or well at the point 13, for the reception ofthe motor and the apparatus by which the disk-carrying turntable isoperated.

ing its base coextensive in one direction with the width of the cabinetand flattened in the other direction to less than half the width of thecabinet, the cabinet having a partitionboard upon the lower edge ofwhich the inner base edge of one long side of the pyramid is supported,the opposite side of the said pyramidal section extending farther andbeing supported'from a side wall of the cabinet, a semi-cylindricaldiaphragm extending from the end of said latter side of the initialsection and at its other end being supported from the opposite side,wall of the cabinet and intermediate these points being out of contactwith the cabinet, said curved diaphragm extending laterally clear acrossthe cabinet, a diaphragm extending from the end ofthe said curveddiaphragm substantially tangent thereto and spaced from the adjacentwall of the cabinet, a curved diaphragm extending from the upper ,edgeof the partition board and curving over with outer end substantially inalmement with the said tangentially placed diaphragm and separated fromthe edge thereof to form a mouth for the amplifying horn.

7 Signed at Seattle, Washington, this'l ith day oflNovember, 19'18. v l

CARL HJALMAR LARSSON:

